A meeting was held by the N.C.I. last year to which most of the people who have worked with Poly ICLC were invited. The one important conclusion from the clinical and preclinical observations is that Poly ICLC should be used at lower levels than we have been using it. The use of lower levels maximizes its immune enhancing activity; there being an optimum drug level above which there is actually decreased effectiveness and increased toxicity. It also was revealed that Poly ICLC is the most effective biologic response modifier that the N.C.I. has tested. Modest, but significant, clinical improvement has been seen in juvenile laryngopapilloma, multiple myeloma and multiple sclerosis, but not leukemia, breast cancer or neuroblastoma at the high drug levels used.